When taking dental radiographs, it is common to expose more than one film packet for each individual patient. In each exposure for straight-forward dental cavity detection, it is necessary to align the x-ray source in a manner to be perpendicular (orthogonal) to the plane of the recording film to achieve sharp images.
One common technique is to use film packets with an attached flap which the patient clenches between his or her teeth. The x-ray machine operator then estimates the correct angle at which to position the x-ray machine so as to achieve orthogonality. The success of this procedure depends on the skill of the operator and the ability of the patient to retain the film packet in his or her mouth without shifting it from the position the operator believes it to be in.
Another technique is to affix the film packet in an apparatus such as described in U.S. Pat. No. 3,473,026 (Updegrave), which rigidly holds the film packet with respect to a biteblock and an x-ray unit aligning rod upon which is affixed a device for positioning the x-ray unit. The device described in Updegrave is constructed in such a manner so as to position the film packet at a predetermined angular relationship to the axis of the x-ray machine for taking specific exposures suitable for endodontic dental investigations. The device described by Updegrave, however, is not adjustable for positioning the film packet so as to take radiographs of either upper or lower teeth in either the right or left sides of the patient's mouth.
Another device, which provides a means to align a film packet with the axis of an x-ray machine is described in U.S. Pat. No. 4,866,750 (Chavarria, et al.). The six major components of the described device can be manipulated to provide a multitude of angles and positions of the film packet relative to the axis of the x-ray machine. Unfortunately, the device disclosed in Chavarria is complex and cumbersome to readjust so that a variety of exposures of the patient's mouth cannot be made quickly.
Thus, the above-described devices have the common deficiencies of being cumbersome or difficult to readjust for subsequent exposures, composed of multiple pieces which would make them difficult to sterilize, and being costly to manufacture. As recognized by the present invention, however, it is possible to provide a film holder for dental x-rays that is convenient to use and that overcomes the above-noted deficiencies.
Accordingly, it is an object of the present invention to provide a film holder for dental x-rays that can be easily configured for holding film on either side of a patient's mouth. Another object of the present invention is to provide a film holder for dental x-rays that establishes a means for aligning an x-ray machine with dental film in a patient's mouth. Still another object of the present invention is to provide a film holder for dental x-rays that is easy to use and cost effective to manufacture.
Other features of the present invention are disclosed or apparent in the section entitled: "BEST MODE FOR CARRYING OUT THE INVENTION."